@misc{indiciaebf4318d61396,
  title = {Rapids of the Colorado River, Grand Canyon, Arizona},
  author = {S. W. Kieffer},
  year = {1986},
  doi = {10.3133/ofr86503},
  url = {https://pubs.usgs.gov/publication/ofr86503},
  note = {Source identifier: ofr86503}
}